class Request {
  constructor(options = {}) {
    // 请求的根路径
    this.baseUrl = options.baseUrl || '';
    // 请求的 url 地址
    this.url = options.url || '';
    // 请求方式
    this.method = 'GET';
    // 请求的参数对象
    this.data = {};
    // header 请求头
    this.header = options.header || {};
    this.beforeRequest = null;
    this.afterRequest = null;
  }

  get(url, data = {}) {
    this.method = 'GET';
    this.url = this.baseUrl + url;
    this.data = data;
    return this._();
  }

  post(url, data = {}) {
    this.method = 'POST';
    this.url = this.baseUrl + url;
    this.data = data;
    return this._();
  }

  put(url, data = {}) {
    this.method = 'PUT';
    this.url = this.baseUrl + url;
    this.data = data;
    return this._();
  }

  delete(url, data = {}) {
    this.method = 'DELETE';
    this.url = this.baseUrl + url;
    this.data = data;
    return this._();
  }

  _() {
    // 清空 header 对象
    this.header = {};
    // 请求之前做一些事
    this.beforeRequest && typeof this.beforeRequest === 'function' && this.beforeRequest(this);
    // 发起请求
    return new Promise((resolve, reject) => {
      uni.request({
        url: this.url,
        method: this.method,
        data: this.data,
        header: this.header,
        fail: (err) => { reject(err); },
        complete: (res) => {
          // 请求完成以后做一些事情
          this.afterRequest && typeof this.afterRequest === 'function' && resolve(this.afterRequest(res));
        },
      });
    });
  }
}

const request = new Request();
export default request;